Shielded metal arc welding is another name for stick welding. In this method, flux coated electrodes are used to create the weld. Most commonly used welding technique; there are several methods of stick welding. These are electric arc welding, gas flame welding, laser welding and ultra sound welding. Stick welding is commonly used to weld together iron, steel, copper, aluminum and some alloys. Many welders favor this method because it is economical and employs simple device.
In shielded metal arc welding, the electrodes and the pieces to be welded form the welded circuit. The electric arc is formed when the electrodes are connected to the voltage source. The metal from the electrodes transfers to the pieces to be joined thus creating the weld. The electric current to be used will depend on the size of the pieces to be welded.
Essentials of Stick Welding
- Current Setting
The electrode to be used determines the current setting, which is specified in the electrode packaging. It will be wise to increase the current in increments of 5 amps at a time until the desired current is reached. Too low a current will make the electrode sticky while higher current will scorch the electrode.
- Arc Length
The general rule is that the arc length should not be greater than the diameter of the metal part of the electrode. If the electric arc is short, the electrode might stick to the pieces to be welded. If the electric arc is large, it will spatter and cause an undercut.
- Electrode Angle
The electrode angle will depend on the welding area. If the welding area is horizontal, the electrode should be at a 15 degree angle to towards the direction of your movement. If the welding area is vertical, the angle is the same but the direction is away from your direction of movement.
- Electrode Manipulation
This technique is acquired through lots and lots of practice. You can also observe the experienced welders and learn the technique from them.
- Travel Speed
The electrode should be at the leading 1/3 of the weld pool. Poor alignment will result from moving the electrode too slow. Moving the electrode too fast will cause undercuts.